The Sun

7/19/18

Rare alignment of planets on one side of the Sun
means that the barycenter of our Solar System
is the farthest it can be from the Sun's surface.
Unfortunately, this guy didn't seem to be aware of it (3:14):

Summary: long gamma ray bursts originate from collapsing stars
and short gamma ray bursts originate from the merger of two super dense objects.
(now we finally know what that bright flash was,
at the wedding of Jim Carrey and Jenny McCarthy)

When we calculate the Earth's age,
we do so by counting the Earth's trips around the Sun.
To be consistent, the age of our solar system
should be calculated in the same manner
(how many times our solar system has orbited the galactic center);
not by how many times one planet has circled its star
during our solar system's existence.
However, that second calculation is far more useful to us
and better helps us to understand our universe.

He assumed a static universe, and that bias denied him his greatest triumph.
He would have been granted the status of a God
had he predicted the expanding universe that Hubble discovered ...
less than a decade later.

Fantastic video, but with one tiny little slip:
5 minutes before the end he says that the light from the Recombination
(the Cosmic Microwave Background Radiation)
has been traveling for 13.7 billion years.
Then he thought he had made a mistake and said that he meant
that the light had been traveling 13.4 billion years.
He was actually correct the first time
because 300,000 years from 13.7 billion is 13.7 billion
not 13.4 billion (he obviously subtracted .3 billion instead of .3 million).
Given the superb quality of his lecture though ...
I think we can cut him some slack on that one.

(Note: recently scientists have refined the age of the universe to 13.8 billion years)

Due to the vast distances between stars
(it would take 75,000 years just to get to the nearest star)
I had pretty much resigned myself to the belief that,
though we might send spacecraft to other solar systems,
humans would likely be confined to living in just our solar system.

However, thanks to recent advances in technology
(like EM drive - if&nbsp it proves to be feasible)
the trip might be reduced to about 100 years. So ...